<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="test"></div>


  <script src="../js/react.development.js"></script>
  <script src="../js/react-dom.development.js"></script>
  <script src="../js/babel.min.js"></script>
  <!-- props限制 -->
  <script src="../js/prop-types.js"></script> 

  <script type="text/babel">
    class Demo extends React.Component {

      state = {isHot: true}

      showData = () => {
        const {input1} = this
        alert (input1.value)
      }

      changeWeather = () => {
        const {isHot} = this.state
        this.setState ({isHot: !isHot})
      }

      saveInput = (c) => {
        this.input1 = c
        console.log ('@', c)
      }

      render () {
        const {isHot} = this.state
        return (
          <div>
            <h2>今天天气很{isHot? '炎热' : '寒冷'}</h2>
            {/*<input type="text" name="" ref={(c)=>{this.input1 = c; console.log ('@', c)}} placeholder='点击按钮提示数据'/>&nbsp;*/}
            <input type="text" name="" ref={this.saveInput} placeholder='点击按钮提示数据'/>&nbsp;
            <button  onClick={this.showData} >点我提示数据</button>&nbsp;
            <button onClick={this.changeWeather}>切换天气</button>
          </div>
        )
      }
    }
    

    ReactDOM.render (<Demo />, document.getElementById ('test'))


   
  </script>
</body>
</html>